1. Field of the Invention
Aspects of embodiments relate to a superhydrophobic substrate, and more particularly, to a superhydrophobic substrate having a water contact angle of 140 degrees or greater and a method of manufacturing the same.
2. Description of the Related Art
A superhydrophobic substrate indicates a substrate having a water contact angle greater than that of a hydrophobic substrate according to the related art, by forming an air gap in an interface between a substrate and water through a concave-convex pattern formed in a substrate surface. An existing hydrophobic substrate has a contact angle of approximately 100 to 110 degrees, while a superhydrophobic substrate has a contact angle of 140 degrees or greater.
In general, a superhydrophobic substrate may be classified as a structure in which an interval between convex portions in a concave-convex pattern formed in a surface of the substrate (an average interval between the convex portions of the pattern) is smaller than an interval between light beam wave peaks of light within the visible spectrum, and a structure in which an interval between convex portions in a concave-convex pattern formed in a surface of the substrate is greater than an interval between light beam wave peaks of light within the visible spectrum. When the interval between the convex portions in the concave-convex pattern formed in a superhydrophobic substrate surface is greater than an interval between light beam wave peaks of light within the visible spectrum, since the interval between the convex portions in the concave-convex pattern is relatively great and durability is present but the substrate is opaque, visibility cannot be secured. When the interval between the convex portions in the concave-convex pattern formed in a superhydrophobic substrate surface is smaller than an interval between light beam wave peaks of light within the visible spectrum, since a substrate is transparent and visibility can be secured but the interval between the convex portions in the concave-convex pattern is relatively small, durability may be degraded and a manufacturing process may be complicated.
Meanwhile, as a method of manufacturing a superhydrophobic substrate, in general, there have been used a method of distributing nanoparticles to form a concave-convex pattern on a substrate, a method of forming a concave-convex pattern through a photolithography process, and a method of forming a concave-convex pattern using electrospraying, but the methods described above have been somewhat problematic, in that substrate surface characteristics, for example, the size and distribution of portions of a pattern formed in a substrate surface, and the like, and optical characteristics of a substrate, for example, transparency and the like, cannot be controlled.